Die-stock.



DIE STOCK. lAPPLICATION FILED 001218, i909.

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H. W. 0STBR. DIE STOCK, APPLIOATIVONIILED 00T. 13,-1909.

979,790. l I Patented nee. 27, 1910.

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DIE STOGK.

APPLICATION FILED 001218, 1909;

Patented Dec.27,1910.

Wa'n e 6 Je s 520672 140710 UNITED srrns PATENT orc HERMAN W. OSTER, OF CLEVELAND, OHIO, ASIGNOR TO THE OSTER MANUFACTURING COMPANY, OF CLEVELAND, OI-IIO, A CORPORATION OF OHIO.

DIE-STOCK.

To all whom it may concern:

Be it known that I, HERMAN IV. OSTER, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Die-Stocks, of which the following is a full, clear, and exact description.

The object of this invention is to provide a die stock with which taper threads may be cut on pipes and other cylindrical bodies; and which permits the removal of the die stock from the work after the thread is cut, without screwing it backward.

rlhe invention is shown embodied in a hand tool in the best form known to me; and it consists in the combination of parts shown in the drawings and hereinafter described and pointed out definitely in the claims.

In the drawing, Figure l is a front end view of a die stock embodying the invention. Fig. 2 is a sectional view in the plane indicated by line 2 2 on Fig. l. Fig. 3 is a central longitudinal section in the plane indicated by line 3 3 on Fig. l. Fig. 4 is a central longitudinal sect-ion in the plane of line 4 4 on Fig. 1. Fig. 5 is a longitudinal section on line 5 5 on Fig. l intended particularly to show one of the springs N and its connections. Fig. 6 is a central longitudinal section in the plane of line 3 3 but showing the parts in the position they will occupy after the thread has been cut and the ,dies retracted to permit the removal of the tool from the work. Fig. 7 is a longitudinal section on line 7 7 on Fig. l showing the spring plunger M.

The body A is a tubular shell having, at what may be termed its front end, four (more or less) die holders a, and, outside of them, a flange a. If the invention is to be embodied in the hand tool, the body is formed with two sockets a2 to receive operating handles. In the rear end of the body the radial movable guides H are mounted, and they may be moved inward and outward to center the tool upon the work by means of a cam plate J having cam-shaped ribs which enter grooves 7L in the rear faces of said guides. In the holders a are radial guideways a3 in which the dies B are slidably fitted, said guideways having the flanges at which overhang the dies and engage with them, whereby said dies are permitted to move in radial directions only.

Specification of Letters Patent.

Patented Dec. 27, 1910.

Application filed October 18, 1909. Serial No. 523,138.

A ring D is slidingly fitted in the flange a. In the inner periphery of this ring the longitudinally extended grooves cl are cut, the outer walls CZ of which are tapered or inclined to the axis of the tool at an angle corresponding with the required taper of the threads to be cut upon the pipe. The outer ends of the dies are correspondingly tapered. The outer portions of the dies enter these slots, and their outer ends engage with the inclined surfaces CZ', said engagement governing the radial outward movement of the dies. It will be understood that the projection of the outer ends 'of the dies into the grooves d compels the ring to turn with the die stock body, but permits the relative longitudinal movement of said parts. The grooves Z are deepened, as by cutting away their outer walls, for about the rear half of the width of the ring. A bar E is fixed to this ring and extends across the center of the die stock so as to be engaged by the end of the pipe F which is being threaded. In one side of each die is an inclined groove Z). Pins Gr are driven into the ring so as to project into the grooves said pins being near the rear end of the ring.

The operation of the described tool is as follows: The pipe F is secured in a vise; and the die stock passed over its end, the parts thereof being then in the relative positions shown in Fig. 3. The guides H are then moved inward int-o engagement with the pipe so as to center it, althougl1 they must not bear against the pipe hard enough to prevent the die stock from turning and moving longitudinally upon the pipe. As the die stock is turned, t-he dies begin to cut the thread on the pipe, and consequently the die stock moves longitudinally on the pipe as it is turned. The bar E, however, by engaging with the end of the pipe F, is prevented from so moving. This causes the relative forward movement of the ring E in the die stock. As said ring does so move forward relatively, the dies are permitted to move gradually outward, and therefore to taper the thread being cut upon the pipe. When the thread has been out, the operator may take hold of the bar E and pull it forward, thereby moving the ring to the position shown in Fig. 6. In moving to this position the pins Gr enter the slots b and compel the dies to move rapidly outward so that they clear the thread, as shown in said Fig.

6, the outer ends of the dies retiring into the j riphery longitudinal grooves which Anear the deepened parts of the grooves d. So long as the dies remain in this position the die stock may be removed from the work without being turned backward.

A spring plunger M is mounted in the die stock body so that when the ring D is pulled out to the position shown in Fig. 6, said plunger will fly behind the ring and revent its backward movement. In order t facilitate the return of the parts to their initial position, as shown in F ig. 3, a contractile coil spring N may be employed. It is placed in a longitudinal socket cl3 in the ring D, which socket is alined with a hole a5 in the body. The front end of this spring is hooked over a pin Zt driven into the ring D; and the rear end of said spring hooks over a pin P which lies against the rear face of the part of the die stock in which the hole a5 is formed. When the plunger M is drawn outward the spring draws the ring D rearward and thereby the pins G operating in slots do move the dies inward, and,l after that, the inclined surfaces d still further move them inward to the required starting position.

Those persons who are familiar with this art understand that die stocks are sometimes made as herein shown, without a work holder, andsometimes with a workholder adapted to be fixed to the pipe to be threaded. In die stocks of the latter type the die stock bodyis adapted to turn and to move longitudinally relatively to the work holder. It has not been thought necessary to show the present invention adapted and applied to die stocks of this latter type, because no claims are made herein specifically applying thereto. But it is intended that the lappended claims shall not be limited to die stocks of the particular type herein shown and above referred to unless the limitation is plainly expressed therein.

I-Iaving described my invention, I claim:

l. In a die stock, the combination of a tubular body having at its front end die holders provided with radial guideways, and having outside of said holders a cylindrical flange, a ring which is fitted in said cylindrical fiange and has in its inner pefront end of the ring have tapered outer walls and which are abruptly deepened near the rear end of said ring, dies movably mounted in said radial guideways and projecting at their outer ends into the grooves in said ring and into engagement with the tapered outer walls thereof, and a bar fixed to said ring and extending across the central opening in the die stock body.

2. In a die stock, the combination ofv a tubular body having at its front end die holders provided with radial guideways, and having outside of said holders a cylindrical flange, a ring which is fitted in said cylindrical flange and has in its inner periphery longitudinal grooves whose outerV walls are tapered, dies movably mounted in said radial guideways and projecting at their outer ends into the grooves in said ring and into engagement with the tapered outer walls thereof, a bar fixed to said ring and extending across the central opening in the die stock body, and a spring latch for holding the said ring in its outdrawn position and a spring which acts to draw saidv ring inward.

3. In a die stock, the combination of a tubular body having at its front end die holders provided with radial guideways, and having outside of said holders a cylindrical flange, with a ring which is fitted in said cylindrical flange and has in its inner periphery longitudinal grooves which are deepened near the rear end of said ring, dies movably mounted in said radial guideways and projecting at their outer ends into the grooves in said ring and into engagement with the outer walls thereof, each o-f said dies having in one side an inclined groove, and pins fixed to the ring projecting into the longitudinal grooves thereof adapted when the ring is moved forward to enter the grooves in the dies.

In testimony whereof, I hereunto affix my' signature in the presence of two witnesses..

Y HERMAN WV. OSTER.

Vitnesses:

E. L. THURsToN, H. R. SULLIVAN. 

